What’s nitrogen？
Nitrogen, with the chemical formula N₂, is a colorless and odorless gas. Nitrogen is chemically inactive. Nitrogen can only react with hydrogen to form ammonia at high temperatures and pressures and under catalyst conditions. Nitrogen can only combine with oxygen to form nitrous oxide under electrical discharge conditions. Even reactive metals such as Ca, Mg, Sr, and Ba can only react with nitrogen when heated.
The atmosphere contains approximately 40 trillion tonnes of gas, nitrogen accounts for 78%. Nitrogen is slightly soluble in water and alcohol. It is non-flammable and considered an asphyxiating gas (i.e., breathing pure nitrogen deprives the body of oxygen). Although nitrogen is an inert element, it forms some very reactive compounds. It can be used as a diluent to control the natural rate of combustion and respiration. At higher concentrations of oxygen, it burns and breathes faster. Nitrogen is soluble in water and alcohol but largely insoluble in most liquids. It is essential in life. Nitrogen compounds can be used as food or fertilizer. We can use nitrogen in the production of ammonia and nitric acid. Nitrogen is essentially an inert gas at room and medium temperatures. Therefore, most metals can be easily dealt with. However, nitrogen can be aggressive to metals and alloys at high temperatures.
2. What’s a flow meter？
A flow meter is an instrument that indicates the flow rate and/or the total amount of fluid measured at a selected time interval. In simple terms, it is an instrument used to measure the flow of fluid in a pipe or open channel.
Flow meters can be classified as differential pressure flow meters, rotor flow meters, throttle flow meters, slit flow meters, volumetric flow meters, electromagnetic flow meters, ultrasonic flow meters, etc. In addition, the medium flowmeter can also be divided into a liquid flowmeter and a gas flowmeter.
3. What’s a nitrogen flow meter？
There are many nitrogen flowmeters. Common is the vortex flowmeter and thermal gas flowmeter.
The vortex flowmeter for nitrogen is manufactured using the Carmen vortex principle. It has the advantages of high measurement accuracy, wide range, low power consumption, easy installation, simple operation, and low-pressure loss. It can measure working volume flow or standard volume flow (integrated intelligent temperature and pressure compensation). The user needs to equip with a pulse or 4 to 20 mA DC output. It is the ideal instrument for measuring nitrogen.
The thermal gas mass flow meter is an instrument that uses the thermal diffusion principle to measure the flow of gases. The sensor consists of two RTDs (thermal resistance devices) at the reference level. One is a velocity sensor RH, and the other is a thermistor RMG, which monitors gas temperature changes. When these two RTDs are placed in the gas being measured, one sensor RH is heated, and the other sensor RMG is employed to sense the temperature of the gas being measured. As the gas flow rate increases, more heat is absorbed by the gas stream, while the temperature of sensor RH decreases.